(shutdwn): Rev. 1.51 broke the Linux pthread hack. It is unclear what

this hack is trying to achieve.  It never worked without -d, because
mainpid got assigned the wrong pid.  It doesn't make sense with recent
versions of Linux pthreads, which use the same PID for all threads, as
required by POSIX.  Remove.  Closes #1161397.

src/server/main.c

@@ -421,29 +421,6 @@ shutdwn(int sig)
     struct player *p;
     time_t now;
 
-#if defined(__linux__) && defined(_EMPTH_POSIX)
-/* This is a hack to get around the way pthreads work on Linux.  This
-   may be useful on other platforms too where threads are turned into
-   processes. */
-    if (getpid() != mainpid) {
-	empth_t *me;
-
-	me = empth_self();
-	if (me && me->name) {
-	    if (strlen(me->name) > 5) {
-		/* Player threads are cleaned up below, so just have
-		   them return.  This should work. */
-		if (!strncmp("Player", me->name, 6)) {
-		    return;
-		}
-	    }
-	}
-	/* Not a player thread - must be server thread, so exit */
-	empth_exit();
-	return;
-    }
-#endif
-
     logerror("Shutdown commencing (cleaning up threads.)");
 
     for (p = player_next(0); p != 0; p = player_next(p)) {